• Chest X-Ray Open or Close

    In medicine, a chest radiograph, commonly called a chest X-ray (CXR), is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are among the most common films taken, being diagnostic of many conditions.

    Chest radiographs are used to diagnose many conditions involving the chest wall, bones of the thorax, and structures contained within the thoracic cavity including the lungs, heart, and great vessels. Pneumonia and congestive heart failure are very commonly diagnosed by chest radiograph. Chest radiographs are used to screen for job-related lung disease in industries such as mining where workers are exposed to dust.

    In the Intensive Care Unit the vast majority of chest X rays will be done with the patient in bed using a portable machine. The use of modern technology enables the immediate visualisation of the image on the portable machine before it is transmitted to a central database for further examination and storage.

     

  • Computerised Tomography (CT) Open or Close

    A computerised tomography (CT) scan uses X-rays and a computer to create detailed images of the inside of the body. 

    CT scans are also sometimes known as CAT scans, which stands for computerised axial tomography.

    During a CT scan, the patient usually lies on their back on a flat bed. The CT scanner consists of an X-ray tube that rotates around the body.

    The X-rays will be received by a detector on the opposite side of the body and an image of the scan will be produced by a computer. 

    The images produced by a CT scan are called tomograms and are more detailed than standard X-rays. CT scans can provide detailed images of many types of tissue, including bone, lung tissue, soft tissue and blood vessels. As a result, CT scans can be used to diagnose and monitor a variety of different health conditions, including brain tumours, certain bone conditions, and injuries to internal organs such as the kidneys, liver or spleen.

    CT scans are often used after serious accidents to look for internal injuries, such as tears in the spleen, kidneys or liver. They're also sometimes used to prepare for further tests and treatments such as radiotherapy treatment or a biopsy (where a small sample of tissue is taken so that it can be examined under a microscope).

    The scan is painless and will usually take between five and 10 minutes depending on the part of the body being scanned.

    For some CT scans, such as those investigating the brain or abdomen, the patient may be given contrast medium beforehand. This is a liquid that contains a dye that shows up clearly on the images of certain tissues or blood vessels. It helps distinguish blood vessels from other structures in the body.

     

    Although CT scans are generally safe, they do expose the body to slightly more radiation than other types of imaging tests. The amount of radiation you're exposed to can vary depending on the type of scan you have.

    In most cases, the benefits outweigh any potential risks because a CT scan can provide your doctor with much clearer images than those produced by a normal X-ray.

    However, CT scans aren't routinely recommended for pregnant women or children. 

  • Echocardiography Open or Close

    An echocardiogram test gives good information about the structure and function of the heart.

    An echocardiogram is an ultrasound scan of the heart. It is sometimes just called an 'ECHO'. Ultrasound is a very high-frequency sound that you cannot hear, but it can be emitted and detected by special machines. The scan can give accurate pictures of the heart muscle, the heart chambers, and structures within the heart such as the valves.

    An ECHO can be carried out for many different reasons. It may be done to check how well your heart is working after a heart attack, or to look at how well the valves are moving inside the heart. An ECHO can also help to see any fluid that may have collected around the heart.

     A probe is placed on the chest (it is a bit like a very thick blunt pen). Also, lubricating jelly is put on thechest so the probe makes good contact with the skin. The probe is connected by a wire to the ultrasound machine and monitor. Pulses of ultrasound are sent from the probe through the skin towards your heart. The ultrasound waves then echo ('bounce back') from the heart and various structures in the heart

    The amount of ultrasound that echoes back depends on the density of the tissue the sound has hit. Therefore, the different structures send back different echoes. For example, ultrasound travels freely through fluid so there is little echo from blood in heart chambers. But, heart valves are dense tissues so ultrasound hitting a valve will echo back clearly.

    The echoes are detected by the probe and are sent to the echocardiogram machine. They are displayed as a picture on the monitor. The picture is constantly updated so the scan can show movement as well as structure. (For example, the valves of a heart opening and closing.) The operator moves the probe around over the skin surface to get views from different angles. Some abnormalities can be seen quite clearly. For example, damaged heart valves, thickened heart muscle, some congenital heart defects, etc. 

    The test is painless and takes about 15-30 minutes.

    Vital information concerning heart function and fluid status can be gained by the use of ECHO on a patient in the ICU. 

     

    Transoesophageal echocardiography

    In this test a probe is inserted into  the patient's oesophagus (gullet) and that is attached to an ultrasound machine. This views the heart from within the oesophagus which lies just behind the heart. This can give a clearer view of the heart than normal echocardiography. It is done in situations where a very detailed picture is needed. For example, to assess valves before surgery is done to repair damaged valves, or to assess the extent of infection of a heart valve.

  • Electrocardiogram (ECG) Open or Close

    The electrocardiogram is a diagnostic tool that is routinely used to assess the electrical and muscular functions of the heart.

    It involves placing special electrodes on the patient's chest and connecting these to a recording machine to produce a tracing of the electrical activity of the heart. The doctors will  look at these tracings to analyse heart function and help to manage subsequent treatment. The examination is entirely painless and without risk and patients in ICU will often have daily ECGs to monitor progress.

    Most patients in ICU will be pemanently connected to a display that shows a continuous recording of the electrical activity of the heart. This connection uses three or four electrodes permanently on the patients chest to produce a waveform thus:

    ECGtrace

    Simple changes to the heart's rate and rhythm can be seen on this monitor. If the doctors require more information then a more detailed examination is carried out, known as a full 12 lead ECG and this is recorded onto a paper strip for subsequent analysis:

    ECGreadout

  • Magnetic resonance imaging (MRI) Open or Close

    Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to visualize detailed internal structures. 

    MRI provides good contrast between the different soft tissues of the body, which makes it especially useful in imaging the brain, muscles, the heart, and cancers compared with other medical imaging techniques such as computed tomography (CT) or X-rays. Unlike CT scans or traditional X-rays, MRI does not use ionizing radiation. 

    The strong magnetic fields and radio pulses can affect metal implants, including cochlear implants and cardiac pacemakers.  Patients with  these devices and/or any other metallic  substance in the body e.g.  shrapnel, metal fragment in the eye etc are  not safe to undergo MRI scanning.

    Patients from ICU who require MRI will be transferred with a specialist team to ensure that all their current therapy can be conintued whilst they are in the scanner. The preparation for the scan and the scan itself can take a considerable period of time so do not worry if your relative is absent from the unit for over an hour.

  • Ultrasound Open or Close

    An ultrasound scan is a painless test that uses high-frequency sound waves, that can be emitted and detected by special machines, to create images of organs and structures inside your body. It is a very commonly used test. As it uses sound waves and not radiation, it is thought to be harmless. Doppler and duplex scans are used to visualise blood or fluids flowing through the body.

     

    • How does ultrasound work?

    Ultrasound travels freely through fluid and soft tissues. However, as ultrasound 'hits' different structures of different density in the body, it sends back echoes of varying strength. For example, the ultrasound will travel freely though blood in a heart chamber. But, when it hits a solid valve, a lot of the ultrasound echoes back. Another example is that when ultrasound travels though bile in a gallbladder it will echo back strongly if it hits a solid gallstone.

     

    • What does an ultrasound scan involve?

    The probe is a bit like a very thick blunt pen. Lubricating jelly is put on your skin so that the probe makes good contact with your body. The probe is connected by a wire to the ultrasound machine, which is linked to a monitor. Pulses of ultrasound are sent from the probe through the skin into your body. The ultrasound waves then echo ('bounce back') from the various structures in the body.

    The echoes are detected by the probe and are sent down the wire to the ultrasound machine. They are displayed as a picture on the monitor. The picture is constantly updated so the scan can show movement as well as structure. For example, the valves of a heart opening and closing during a scan of the heart. The operator moves the probe around over the surface of the skin to get views from different angles.

    The scan is painless and takes about 15-45 minutes, depending on which parts of the body are being examined. A record of the results of the test can be made as still pictures or as a video recording.

     

    • What is an ultrasound test used for?

    It is used in many situations. The way the ultrasound bounces back from different tissues can help to determine the size, shape and consistency of organs, structures and abnormalities. So, it can:

    Help to monitor the growth of an unborn child, and check for abnormalities. An ultrasound scan is routine for pregnant women

    Detect abnormalities of heart structures such as the heart valves. (An ultrasound scan of the heart is called an echocardiogram

    Help to diagnose problems of the liver, gallbladder (such as gallstones), pancreas, thyroid gland, lymph nodes, ovaries, testes, kidneys, bladder and breast. For example, it can help to determine if an abnormal lump in one of these organs is a solid tumour or a fluid-filled cyst.

    Detect abnormal widening of blood vessels (aneurysms).

     

    • Some specialist ultrasound techniques

    In some situations, a clearer picture can be obtained from a probe that is within the body. So a small probe, still attached by a wire to the ultrasound machine, can be:

    Swallowed into the gullet. This is sometimes used to get clearer images of the heart, which lies just in front of the gullet.

    Placed in the vagina or rectum to get clearer images of the pelvic and reproductive organs.

    Used to help guide a surgeon during an operation, in order to look deeper into structures.

     The above are not exhaustive lists, and ultrasound scanning has various other uses.

     

    A Doppler ultrasound records sound waves reflecting off moving objects, such as blood cells, to measure their speed and other aspects of how they flow through the body.

     

    • How does Doppler ultrasound work?

    If the structure is moving then the echo comes back at a slightly different frequency (called the Doppler effect). This difference in frequency can be used to measure the speed of movement. Blood moving in an artery or vein causes small echoes and these are used to measure the speed of movement of the blood cells. The sound waves may be amplified though speakers.  This allows the practitioner to listen to the flow of blood cells to determine whether or not there is normal flow (for example, listening to the flow of blood through the heart of a baby during a routine antenatal check-up, or damaged veins or arteries following an injury). The sound waves may also be converted to colour pictures on a screen so that flow can be seen through the arteries or veins (colour Doppler), or on a graph showing changes in velocity.

    • What is Doppler ultrasound used for:

    To listen to the heartbeat of an unborn baby (fetus) during pregnancy.

    To examine blood flow in arteries or veins in your arms or legs to see if you might have:

       Deep vein thrombosis

       Peripheral vascular disease

       Injury to your veins or arteries following trauma

     

    • What does a Doppler ultrasound involve?

    During pregnancy, the Doppler ultrasound is very similar to an ultrasound scan. A probe covered with gel is put on your skin over the pregnant womb (uterus). This is connected to a speaker and the practitioner simply listens to the flow of blood through the fetus's heart.

    During a Doppler ultrasound of the arms and legs, blood pressure cuffs are placed along the thigh, calf, or ankle, or to different points along the arm. A paste is applied to the skin over the arteries being examined. Images are created as the probe is moved over each area.

    • What is a duplex ultrasound?

    Duplex ultrasound is a special technique which combines traditional ultrasound with Doppler ultrasound. Images of the solid object being examined - for example, the artery and the blood flowing through it - are displayed on a screen or monitor. The object is usually grey and the blood flow is usually in colour (colour Doppler).

     

    • What is duplex ultrasound used for?

    Duplex ultrasound is most commonly used to evaluate the blood flow in various arteries and veins in the body. The scan can help diagnose the following conditions:

    Widening of the main artery in the tummy (abdominal aneurysm).

    Blockage to an artery (an arterial occlusion).

    Blood clot.

    Blockage to the arteries in the neck (carotid occlusive disease).

    Renal duplex examines the kidneys and their blood vessels.

    Varicose veins.

    Venous insufficiency (a condition where veins have a problem sending blood back to the heart

     

    Are there any side-effects or complications from ultrasound, Doppler or duplex scans?

    These scans are painless and safe. Unlike X-rays and other imaging tests, they do not use radiation. They have not been found to cause any problems or complications.